ASUS Maximus III Extreme LGA1156 Motherboard Review

Voltage Regulation / Power Consumption

Our voltage regulation testing will focus on the various voltages and the differences encountered between what is selected in the BIOS and what is measured by a digital multi-meter (DMM). Thanks to the ProbeIt feature we didn't have to go poking & prodding everywhere, since all the voltage read points are located in one convenient spot. The concept is pretty simple, the left dot is the ground point, the right point is the voltage read point. Touch your DMM leads to whichever voltage you want to check and voila! As mentioned previously though, we would have preferred a design where you could attach the DMM leads to the read points, since it's a pain in the backside to be standing over the motherboard gently keeping the leads on the small dots for any length of time.

Voltage Regulation

These measurements were taken at stock system speeds and with C1E, SpeedStep, Turbo Boost, and Thermal Monitor disabled in the BIOS. Just to clarify, the vCore (LLC) section is the vCore results with Load-Line Calibration enabled. Here are our findings:

As we've come to expect from the Republic of Gamers motherboards, the Maximus III Extreme has excellent output and regulation. What you select in the BIOS is exactly what the motherboards outputs and there is effectively no variance between idle and load states. Having said that, obviously when Load-Line Calibration (LLC) is disabled there is a roughly 5% voltage droop, as per Intel's specifications. Any vDroop is totally elimited when LLC is enabled. Given how critical it is, let's take a closer look at the vCore's characteristics under full load with a one-hour OCCT run, while our Core i7-870 is overclocked to 3.60Ghz at 1.35Vcore with LLC on AUTO:

With Load-Line Calibration disabled, the vCore line droops by a little over 5% under heavy load, which is within spec. We do wish that there weren't any spikes during the test though, but they are relatively minor.

Once Load-Line Calibration is enabled, the vCore line rock-solid and all the spikes are ironed out.

Power Consumption

All motherboard manufacturers boast that their products have the lowest power consumption and feature the latest new development in energy efficiency. Well that is what we are here to find out.

For this test, every BIOS option was reset to its default setting and the Windows Vista power plan was changed from High Performance to Balanced. Lastly, we set the ASUS EPU-6 Engine to AUTO mode to allow it to fully manage system power consumption. We also tan this test without EPU being installed on the system, to see what the difference would be.

For our idle test, we let the system idle for 15 minutes and measured the peak wattage through our UPM EM100 power meter.

For our CPU load test, we ran Prime 95 In-place large FFTs on all available threads for 15 minutes, measuring the peak wattage via the UPM EM100 power meter.

For our overall system load test, we ran Prime 95 In-place large FFTs on all available threads for 15 minutes, while simultaneously loading the GPU with OCCT v3.1.0 GPU:OCCT stress test at 1680x1050@60Hz in fullscreen mode.

Given all the additional controllers (USB 3.0, SATA 6Gb/s, NVIDIA NF200), we weren't surprised that the Maximus III Extreme had higher idle power consumption than the Maximus III Formula. However, as you can see, the MIIIE's newer generation PWM design starts to show its advantage
under full load scenarios. Either way, as we mentioned in the MIIIF review, this is an enthusiast product, so power consumption be damned!

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